Fungos micorrízicos arbusculares na produção de mudas de Albizia polycephala

Abstract

Currently there is a need to produce seedlings at low cost and with high quality to be used in the recovery of degraded areas and the use of arbuscular mycorrhizal fungi (AMF) can improve their development in low fertility soils. AMF have several benefits for the plants, because they promote increased survival and establishment of seedlings in the field, as with the symbiosis hyphae improve water use and nutrients. And before this, the present study aimed to evaluate the growth of seedlings Albizia polycephala inoculated with different AMF. First they were produced inoculants through traps vessels with species of native AMF obtained from samplings in the rhizosphere of matrices Albizia polycephala. Later two experiments were conducted, the first being tested five species of AMF from the Collection arbuscular mycorrhizal fungi of Embrapa Agrobiology (COFMEA), mounted in a completely randomized block design with six treatments (control - without inoculation, Scutellospora calospora (T.H. Nicolson & Gerd.) C. Walker & F.E. Sanders, Acaulospora colombiana (Spain & N.C. Schenck) Kaonongbua, J.B. Morton & Bever, Claroideoglomus etunicatum (W.N. Becker & Gerd.) C. Walker & A. Schüßler, Dentiscutata heterogama (T.H. Nicolson & Gerd.) Sieverd., F.A. Souza & Oehl e Gigaspora margarita W.N. Becker & I.R. Hall) and nine repetitions. In the second experiment inoculants native AMF were tested (native inoculant) and the best species of AMF in the first experiment (Embrapa inoculant). The experimental design was randomized blocks with eight repetitions, in a factorial 3 x 4, that is, three treatments (a witness - no inoculation and two inoculants - native inoculum and mixture of three species from COFMEA) and four doses of P (0, 35, 140 and 350 mg/dm³), applied in the form of superphosphate. The seed Albizia polycephala germinated in trays with sand and vermiculite (2: 1with based on volume) and when the seedlings had a pair of leaves were transplanted with the inoculant in plastic containers of 700 ml with PVC cartridge 380 cm³ coupled your background. During the experiments were conducted biweekly measurements of height and diameter and after collection, the root colonization rate assessments, spore density, dry matter of shoot, root dry matter, reason root /shoot and leaf phosphorus content . The results obtained through the evaluations showed that the species of Acaulospora colombiana was the most effective in promoting the growth of Albizia polycephala. Furthermore, the inoculant of COFMEA provided better growth in different phosphorus levels than native inoculant. Thus, it can be stated that the tested species has association with AMF efficiently and has high dependence mycorrhizal.